Multi-speed transmission

Abstract

A transmission of the present invention has an input member, an output member, four planetary gear sets, a plurality of coupling members and a plurality of torque transmitting devices. Each of the planetary gear sets includes first, second and third members. The torque transmitting devices may include clutches and brakes. The torque transmitting devices are selectively engageable in combinations of at least two to establish at least nine forward speed ratios and at least one reverse speed ratio.

What is claimed is: 
     
       1. A transmission comprising:
 an input member; 
 an output member; 
 first, second, third and fourth planetary gear sets each having first, second and third members, wherein at least one of the first, second, and third members is directly connected to at least one other of the first, second, and third members to form each of at least a first, a second, and a third rotary member; 
 a first torque transmitting device selectively engageable to connect the first rotary member with the second member of the fourth planetary gear set; 
 a second torque transmitting device selectively engageable to connect the second member of the second planetary gear set with the first member of the fourth planetary gear set; 
 a third torque transmitting device selectively engageable to connect the second rotary member with a stationary member; 
 a fourth torque transmitting device selectively engageable to connect the third member of the first planetary gear set with the stationary member; 
 a fifth torque transmitting device selectively engageable to connect the second member of the fourth planetary gear set with the stationary member; and 
 a sixth torque transmitting device selectively engageable to connect the third rotary member with the stationary member, and 
 wherein the torque transmitting devices are selectively engageable to establish a plurality of forward speed ratios and at least one reverse speed ratio between the input member and the output member, and 
 wherein at least four torque transmitting devices are disengaged in each of the plurality of forward speed ratios and the at least one reverse speed ratio. 
 
     
     
       2. The transmission of  claim 1  wherein the third member of the first planetary gear set, the first member of the second planetary gear set, the first member of the third planetary gear set and the third member of the fourth planetary gear set are sun gears, the second member of the first planetary gear set, the second member of the second planetary gear set, the second member of the third planetary gear set and the first member of the fourth planetary gear set are carrier members and the first member of the first planetary gear set, third member of the second planetary gear set, the third member of the third planetary gear set and the second member of the fourth planetary gear set are ring gears. 
     
     
       3. The transmission of  claim 1  wherein the input member is continuously directly connected with the first rotary member and the output member is continuously directly connected with the first member of the fourth planetary gear set. 
     
     
       4. The transmission of  claim 1  wherein the stationary member is a transmission housing. 
     
     
       5. The transmission of  claim 1  wherein the first members of the first, second, and third planetary gear sets are continuously directly connected to form the first rotary member. 
     
     
       6. The transmission of  claim 1  wherein the second member of the first planetary gear set, the second member of the third planetary gear set, and the third member of the second planetary gear set are continuously directly connected to form the second rotary member. 
     
     
       7. The transmission of  claim 1  wherein the third member of the third planetary gear set and the third member of the fourth planetary gear set are continuously directly connected to form the third rotary member. 
     
     
       8. The transmission of  claim 1  wherein the fourth and fifth torque transmitting devices are engaged in a first of the at least one reverse speed ratio. 
     
     
       9. The transmission of  claim 8  wherein the third and fifth torque transmitting devices are engaged in a first of the plurality of forward speed ratios. 
     
     
       10. The transmission of  claim 9  wherein the second and fifth torque transmitting devices are engaged in a second of the plurality of forward speed ratios. 
     
     
       11. The transmission of  claim 10  wherein the third and second torque transmitting devices are engaged in a third of the plurality of forward speed ratios. 
     
     
       12. The transmission of  claim 11  wherein the sixth and second torque transmitting devices are engaged in a fourth of the plurality of forward speed ratios. 
     
     
       13. The transmission of  claim 12  wherein the fourth and second torque transmitting devices are engaged in a fifth of the plurality of forward speed ratios. 
     
     
       14. The transmission of  claim 13  wherein the first and second torque transmitting devices are engaged in a sixth of the plurality of forward speed ratios. 
     
     
       15. The transmission of  claim 14  wherein the first and fourth torque transmitting devices are engaged in a seventh of the plurality of forward speed ratios. 
     
     
       16. The transmission of  claim 15  wherein the first and sixth torque transmitting devices are engaged in an eighth of the plurality of forward speed ratios. 
     
     
       17. The transmission of  claim 16  wherein the first and third torque transmitting devices are engaged in a ninth of the plurality of forward speed ratios. 
     
     
       18. A transmission comprising:
 an input member; 
 an output member; 
 first, second, third and fourth planetary gear sets each having first, second and third members, wherein the first members of the first, second, and third planetary gear sets are continuously directly connected to form a first rotary member, wherein the second member of the first planetary gear set, the second member of the third planetary gear set, and the third member of the second planetary gear set are continuously connected to form a second rotary member, and the third member of the third planetary gear set and the third member of the fourth planetary gear set are continuously connected to form a third rotary member; 
 a first torque transmitting device selectively engageable to connect the first rotary member with the second member of the fourth planetary gear set; 
 a second torque transmitting device selectively engageable to connect the second member of the second planetary gear set with the first member of the fourth planetary gear set; 
 a third torque transmitting device selectively engageable to connect the second rotary member with a stationary member; 
 a fourth torque transmitting device selectively engageable to connect the third member of the first planetary gear set with the stationary member; 
 a fifth torque transmitting device selectively engageable to connect the second member of the fourth planetary gear set with the stationary member; and 
 a sixth torque transmitting device selectively engageable to connect the third rotary member with the stationary member, and 
 wherein the torque transmitting devices are selectively engageable to establish a plurality of forward speed ratios and at least one reverse speed ratio between the input member and the output member, and 
 wherein at least four torque transmitting devices are disengaged in each of the plurality of forward speed ratios and the at least one reverse speed ratio. 
 
     
     
       19. The transmission of  claim 18  wherein the input member is continuously directly connected with the first rotary member and the output member is continuously directly connected with the first member of the fourth planetary gear set. 
     
     
       20. A transmission comprising:
 an input member; 
 an output member; 
 first, second, third and fourth planetary gear sets each having a ring gear, a carrier member, and a sun gear, wherein the ring gear of the first planetary gear set and the sun gears of the second and third planetary gear sets are continuously directly connected to form a first rotary member, the ring gear of the second planetary gear set and the carrier members of the first and third planetary gear sets are continuously directly connected to form a second rotary member, and the ring gear of the third planetary gear set and the sun gear of the fourth planetary gear set are continuously directly connected to form a third rotary member, and wherein the first rotary member is continuously directly connected with the input member and the carrier member of the fourth planetary gear set is continuously directly connected with the output member; 
 a first torque transmitting device selectively engageable to connect the first rotary member with the ring gear of the fourth planetary gear set; 
 a second torque transmitting device selectively engageable to connect the carrier member of the second planetary gear set with the carrier member of the fourth planetary gear set; 
 a third torque transmitting device selectively engageable to connect the second rotary member with a stationary member; 
 a fourth torque transmitting device selectively engageable to connect the sun gear of the first planetary gear set with the stationary member; 
 a fifth torque transmitting device selectively engageable to connect the ring gear of the fourth planetary gear set with the stationary member; and 
 a sixth torque transmitting device selectively engageable to connect the third rotary member with the stationary member, and 
 wherein the torque transmitting devices are selectively engageable to establish a plurality of forward speed ratios and at least one reverse speed ratio between the input member and the output member, and 
 wherein at least four torque transmitting devices are disengaged in each of the plurality of forward speed ratios and the at least one reverse speed ratio.